The Effect of Variation in Oven Temperature and Internal Temperature on Cooking Losses, Tenderness and Visual Acceptability of Pork Roasts

(From the Introduction)

For many years, it has been believed that pork to be safe for human consumption must be cooked to the well-done stage in order to destroy spores of Trichinella spiralis which are not detected by meat inspection methods. For this reason recipes for roasting fresh pork usually reconmend using an oven tempera­ ture of 325°F. or 350°F. and cooking to an internal temperature of from 180°F. to 185°F. However, recent regulations concerning commercial processing of pork require that pork be heated only to 137°F. internal temperature, which has been demonstrated as satisfactory for the complete destruction of the spores of Trichinella spiralis (U. S. Department of Agriculture, 1960). In 1961, Webb, et al. recommended 149°F. as a minimum internal temperature for roasting fresh pork to allow a margin of safety. Current home practice would seem to involve excessive heat treatment. In view of the discrepancy between commercial and current home practice, it seemed desirable to test the suitability of using lower oven and/or internal temperatures for roasting pork.

Pork loin roasts from Duroc and Hampshire boars finished on the same basic ration were used in this study. The internal temperature at the center of the roasts was used as the end point for cooking. The internal temperatures tested were 149, 167 and 185°F. The first two temperatures are lower than commonly recorrunended for pork cookery. The lowest internal temperature tested in this study, 149° F., corresponds to the rare stage for beef and as suggested by Webb, et al. (1961) permits a safety margin for the destruction of the Trichina organism. The 185°F. internal temperature was representative of current home practice.

Numerous studies have indicated that low cooking temperatures improve the sensory quality of beef, especially tenderness; however, few studies have been concerned with cooking pork at low temperatures. For this reason it seemed desirable to test cooking at lower oven temperatures as well as to test reduced internal temperatures. The oven temperatures employed in this study were 250, 300 and 350°F., the first two being lower than currently recorrunended for fresh pork and 350°F. being representative of current home practice.

Therefore, in this study, nine combinations of oven and internal temperatures were employed for roasting fresh loin of pork. The data included evaluations of tenderness by shear values, cooking losses, cooking times, visual estimates of acceptability from the standpoint of color, moistness and appearance and the per cent moisture and ether extract of the cooked roasts.